Fluid buffer for elevators



May 8, 1956 w. BECK 2,744,587

FLUID BUFFER FOR ELEVATORS Filed Sept. 27, 1952 3 Sheets-Sham'l l May 8, 1956 w. BECK 2,744,587

FLUID BUFFER FOR ELEVATORS Filed Sept. 27, 1952 3 Sheets-Sheet 2 EUR 'Immun May 8, 1956 w. BECK 2,744,587

FLUID BUFFER FOR ELEVATORS Filed Sept. 27, 1952 3 Sheeos-Sheeil 5 I* Il United States Patent O 2,744,581 Y FLUID BUFFER FOR ELEvAToRsv Walter Beck, Rock Island, `lll., assignor to Montgomery Elevator Company, a corporation of illinois Application September 27, 1952, Serial No. 311,901

6 Claims. (ci. 1s767) This invention-relates to improvements yin fluid elevator buiers and particularly to improvementsin construction which reduce the cost, facilitate the servicing and improve the operation of such bullers.

For many years, iluid buffers have been used as safety devices with elevators. Basically, such buierscomprise a uid llled cylinder with a piston movable therein. lThe buffer is placed at the bottom of the elevator pit in such a position that'the piston rod will be contacted by the descending elevator cage or counterweight. If all of the other safety devices, such as friction brakes vand. limit switches, should fail and the elevator or the counterweight descend into the pit, its fall will be arrested'and the shock of stopping will be cushioned by the oil `damped piston. In the usual installation, two buffers are providedone for the cage and the other for the counterweight. Generally, these buiers also include a uid reservoir surrounding the cylinder and a rather complex head casting which servesas an auxiliary reservoir and which provides means for guiding the piston rod. The complexity of this head casting lmakes it difficult and costly to manufacture.

One object' of my invention is to provide an fluid elevator buffer. avbuffer in which the reservoir is provided with a substantially planarY closure'member of substantially the same area asthe reservoir, 'so as to avoid the need for a casting with 'a' closed top and a partially closed bottom, with thexresulting complexity of coring the casting. Yet another object' is to provide a buffer in which the cylinder in kwhich the piston travels is shorter than the surrounding reservoir, and the member on top of the reservoir is provided withpos'itioning means which engage the cylinder. Still`an'oth`er objects'is to provide such a buffer with a iiller tube attached tothe reservoir andhaving the point of iilling below the top of thel cylinder.

Further objects and vadvantages `will become apparent from thefollowing specification and from the drawings Fig; lis aside elevation of a lever type elevatori buffer'- showing" the elevatorcage' at ground level;

^ vrligfZ* is la side elevation, similar to Fig. l, but showing the elevator cage'after it has descended into thel'pit, with thebutfer in fully depressedposition; f

' Fig. 3'-`is an enlarged sectional view taken as indicated along the'line'3'-'3 in Fig. 4, with the spring guide membefr removed for ladded clarity;

Fig. 4 is an'end elevation of the buer, viewing Fig.' l from the right, with'some portions in section;

Fig. 5 is a fragmentary sectional 'view taken as indi-y v cated'along the line 5-5 of Fig. 4; and

Fig. k6 is a diagrammatic sketch showing the movementv of the lever and the yoke.

j'In ythe embodiment illustrated in the drawings, .the invention is shown-in connection with a lever type buler as.,opposed toa straight-line, or standard type buffer. Aswill become evident, eitherY type; otbuifer maybe improvedi Another object is to provide such:

relative used. The straight-line buffer is generally installed in locations where the depth of the elevator pit is not critical. The lever type butler was designed for use in situations where for some reason, such as where a building is built on bed rock, it is impractical or impossible to dig a pit deep enough to accommodate a standard buffer which may be almost l1 feet long in extended position and haveV a stroke of 41/2 feet. A representative lever buer may be less than 3 feet long, have a piston stroke of 7 inches and a lever arm movement of 21/2 times the piston stroke.

Referring now to Fig. 1, the'elevator cage 10 is shown with its lloor 11 ush with the ground 12; and a lever4 means 15 so that its descent is arrested by the butler and it comes to rest in the position shown in Fig. 2.

Referring now to Figs. 4 and 5, it will be seen that the lever type butler 13 has a base consisting of a pair ofupright channel members 16, and a transverse channell member17. The base also includes a pair of upright extending legs 13 to which the lever means 15 are pivotally attached.

A reservoir 19 is secured to the transverse channel member 17 and extends upwardly therefrom. As shown here, this reseivoir is cylindrical in shape; but it could take other forms, such as a rectangle.

sealed thereto by means of studs 21 welded to the reservoir and nuts 22. The closure member 20 has roughly' the same cross sectional area as the reservoir, and is substantially planar. The closure member is provided with a downwardly extending positioning boss 23 which extends into the reservoir and is provided with a plurality of radial positioning fins 23a.

- The manner in which the closure member 20 is litted'- to the reservoir 19 should be noted particularly. In the past, these buffers have been constructed with the variousV partsv threaded together, and as the diameters involved were rather large, the reservoir possibly being 8 inchesv in diameter, it was extremely diicult to maintain the desired standards of length or overall dimensions in the finished product. In the butler shown, the abutting surfaces ofthe reservoir and the closure member are finished` with a relatively high degree of accuracy, and the partsy the interior of the cylinder. The function of these aper-v tures and the reason for the particular arrangement used will be explained later. A piston 28 is movable longitudinally in the cylinder, and the piston rings 29 provide a seal between the piston and the walls of the cylinder.

A'hollow, tubular piston rod 30 is affixed to the piston 28 and extends upwardly through a bore 31 in the closure member 20 and boss 23. The end surfaces of the piston rod and the abutting shoulder of the piston lare lnished'l Patented .May .8, 1956.

The top of the` reservoirv 19 is fitted with a closure member 20, which'is d piston rodis provided with a cap 33, the abutting surfaces again being accurately finishedV and the parts'held together by pins 34. An ring 35 provides an airtight seal between the cap 33 and the piston rod 30. A leatherwasher 37 'encircles the piston rod\30 between theY piston 2S'and the positioning boss 23, cushioning the parts during operation. An oil seal 38 in a' recess in the top of the closure member 20 and an O 'ring 39 in the bore 31 provide a uid tight seal between'the closure member and the piston rod 30.

A` coil spring 41 extends between the upper surface of the plug 25 and the bottom surface of the cap 33 and biasestthe piston and piston rod upwardly.' Spring guide member 42 is secured to the base of the 'cylinder and extends longitudinally through thespring to prevent it from buckling when compressed.

A cross 4bar 43 is bolted to the cap 33 and has bearing portions 43d and b at its ends` on which links'44 and 45 are-pivotally mounted to form a yoke structure.V Two bifurcated levers are made up of the' four elongated members-46a, 4Gb, 46c and 46d which are-pivotally attached to ther upright legsv 1S by the pins 59""and to theL links 44` and 45 vby the pins 47 'and 48.l

Rollers 49 are mounted on an axle- 50 at the outer extremity ofithelevers and are adapted to Abel contacted bythe elevator cage-or counterweight as shown in Fig; 6.

The interiorof the piston rod 30 is vented to--theatmospherethrough the vent channel 51. A` checkvalve comprising a ball 52 and annular seatl 53 are provided in` this channel and their operation willA be explained later. shown by the pin 54.

The reservoir 19 may be lled with uid through a tiller.` tube SSfwhich' is threaded into the side of the reservoir. Theiupper end 56 of the filler tube isbelowthe :top of the cylinder, and is closed by a removable plug 57. The level of the uid, which may be a very light oil, in the reservoir is preferably as indicated by the` line 58; It should be noted that the uid entirely lls the cylinder below the piston.

In ythe event-that the descending elevator mechanism engages the lever means upon the failure of the other safeties as previously described, the levermeans is rotated about the pins 59 and the piston 28 moves downwardly. The pressure of the air within the piston rod- Y 30is immediately increased, forcing the ball -52 into the annular seat 53 thereby closing the vent channel 51. Some of the oil within the cylinder 24 is forced up inside-the piston rod, while most of it is ejected fromV the-*cylinder through the apertures 27 into the reservoir. The ring of apertures immediately beneath the piston 28-permits rapid ejection of oil so that the initial movement is rather rapid and the elevator does not receive an excessively severe jar. However, as the pistoncontinues to descendunder the impetus of the elevator mechanism, `there are fewer apertures 27 through which the uid may be ejected into the reservoir so that the descent` of thepiston is slowed-until the bottommost-aperture is passed and the piston and elevator mechanismare the drawings, an electric switch 61V is wired into-the elevator motor and control circuits (not shown), andhasan operating arm 62,` A plate 63 attached 'to' one of Vthelever arms 43 moves the operating ar-m62l'down.'

ward when the buffer is depressed, as shown in FigL--Zf to operate 'the switch 61 and `prevent normaloperation- The ball 52 is normally supported in the position" 4. of the elevator motors and control circuits as long as theA `buter` is depressed.

After a defect has been remedied, the elevator mechanism may be raised from the pit and the buffer will resume its normal position, by virtue of the bias of the spring 41. The vent channel 51 will now be open, facilitating the recovery operation.4 The switch 61 will also return to its normal position, allowing the resumption of normal operation.

While I have shown and described certain embodiments of my invention, it is to be understood that it is capable of many modifications, Changes, therefore, in the construction and arrangement may be made without departing from the spirit and scope of the invention as disclosed in the appended claims.

I claim:

l. A uid elevator buier for use with a vertically reciprocable elevator mechanism, comprising: a base; a uid reservoir mounted on said base, said tluid reservoir having asm'oothly finished top margin; an open'topped cylinder mounted'in said reservoir with its upper end spaced substantially below the top margin of the'reservoir, said'cylinder having a plurality of apertures in its side wall;l an effectively planar closure membery for said uid reservoir, said closure member having its periphery overlyingthe reservoir and having a smoothly finished surface to seat on the top margin of the reservoir; a plurality ofattaching members sealing said closure member on the reservoir; a generally sleeve-like guide boss at the center ofV said closure member, said guide boss extending downwardly lsubstantially to the top of the cylinder and having a plurality ofv outwardly extending spaced positioning fins :engaging the top of the cylinder so as to leave uprightuid channels between the fins; a piston in the cylinder; a piston rod secured to the piston and extending through`4` said guide boss in the closure member, said piston: andpiston rod being adapted to be depressed by the descending elevator mechanism; and means biasing said-piston and-piston rod upwardly.

2. The device of claim 1 in which the attaching memberscomprise means bearing on the top of the closure member andengaging lugs on theiwall of the reservoir.

3. The device of claim l in which the attaching members comprise upstanding threaded lugs on the reservoir which' project above the closure to receive threaded nuts.

4: A' uid elevator buffer for use with a vertically reciprocablefr elevator mechanism, comprising: a base; auid reservoirmounted on said base, said uid reservoir havings-a smoothly finished top margin; an open topped cylindermounted in said reservoir with its upper end spaced 'substantially below the top margin of the reservoir, said' cylinderhaving a plurality of apertures in its` side wall; an: effectively planar closure member for saiduid reservoir, said closure member having its periphery overlyiugfthe reservoir and having a smoothly finished surface toseatfon the top marginef thereservoir; a plurality of attaching members sealing said closure member on the reservoir.; a generally sleeve-like guide boss at the center of said closure member, said guide boss extending downwardly-substantially to the top of the cylinder and 4having' a plurality of outwardly extending spaced positioning tins engaging the top-of the cylinder so as to leave upright uid channels between the tins; a piston in the cylinder; a piston rod secured to the piston and extending through said guide boss in the closure member, said piston and piston-rod being adapted to be depressed by the descending elevatormechanism; means biasing said piston and piston rod upwardly; an elongated lever means attached to said piston rod, one end of said lever means being attached to said base and the other end being positioned to be contacted by the descending elevator mechanism.

5. A fluidfelevator buffer for use with a vertically recprocable Ielevator mechanism, comprising: a base;

a fluid "reservoir mounted on' said base, said tluidreservoir having-'a smoothly iinishedvtop margin; anopen topped` cylinder mounted in said reservoir with its upper end spaced substantially below the top margin of the reservoir, said cylinder having a plurality of apertures in its side wall; an eiectively planar closure member for said Huid reservoir, said closure member having its periphery overlying the reservoir and having a smoothly finished surface to seat on the top margin of the reservoir; a plurality of attaching members sealing said closure member on the reservoir; integral sleeve-like guide means extending downwardly from the closure member into engagement with the top of the cylinder, said guide means having openings adjacent the top of the cylinder providing uid passages between the cylinder and the reservoir; a piston in the cylinder; a piston rod secured to the piston and extending through said guide means in the closure member, said piston and piston rod being adapted to be depressed by the descending elevator mechanism; and means biasing said piston and piston rod upwardly.

6. A uid elevator buter for use with a vertically reciprocable elevator mechanism, comprising: a base; a uid reservoir mounted on said base, said iluid reservoir having a smoothly finished top margin; an open topped cylinder mounted in said reservoir with its upper end spaced substantially below the top margin of the reservoir, said cylinder having a plurality of apertures in its side wall; an effectively planar closure member for said iluid reservoir, said closure member having its periphery overlying the reservoir and having a smoothly nished surface to seat on the top margin of the reservoir; a plurality of attaching members sealing said closure member on the reservoir; integral sleeve-like guide means extending downwardly from the closure member into engagement with the top of the cylinder, said guide means having openings adjacent the top of the cylinder providing fluid passages between the cylinder and the reservoir; a piston in the cylinder; a piston rod secured to the piston and extending through said guide means in the closure member, said piston and piston rod being adapted to be depressed by the descending elevator mechanism; means biasing said piston and piston rod upwardly; and elongated lever means attached to said piston rod, one end of said lever means being attached to said base and the other end being positioned to be contacted by the descending elevator mechamsm.

References Cited in the le of this patent UNITED STATES PATENTS 986,378 Furlow Mar. 7, 1911 1,005,201 Gurney Oct. 10, 1911 1,434,197 Brown, Jr Oct. 31, 1922 1,448,229 Miller et al Mar. 13, 1923 1,473,692 Atkinson Nov. 13, 1923 1,539,323 Neubert et al May 26, 1925 1,714,160 Crowell et al May 21, 1929 1,807,284 Dupont May 26, 1931 1,821,787 Black Sept. 1, 1931 2,191,246 Andersen Feb. 20, 1940 2,565,617 Mercier et a1 Aug. 28, 1951 

